!!!! Do not merge it with standard-test-roles.

Standard-test-behave role is adopted to the dnf-docker tests.

1. tasks includes steps to run runtest.sh script, which will run behave tests under separate docker image, if run_in_background var is defined.

2. run_in_background variable is added with aim for adding possibility to run tests in parallel.

3. Added tests_folder var, specifying folder with runtest.sh script, which takes feature name.

4. Added steps for monitoring of the background docker processes to gather all results for each tests from containers

5. standard_inventory_behave script will be added with dnf_tests, because it adopted for specific needs.